An example of a union : union « Data Types « C++ Tutorial

1. C++ Tutorial
2. Data Types
3. union

#include <iostream>
using std::cout;
using std::endl;

union Number           
{                      
   int integer1;       
   double double1;     
};

int main()
{
   Number value;

   value.integer1 = 100;

   cout << value.integer1 << "\ndouble: " << value.double1
        << endl;

   value.double1 = 100.0;

   cout << value.integer1 << "\ndouble: " << value.double1
        << endl;

   return 0;
}

100
double: 4.24399e-314
0
double: 100